Spectroscopy — the use of light from a distant object to work out the object is made of — could be the single-most powerful tool astronomers use, says Professor Fred Watson from the Australian Astronomical Observatory. ... "It lets you see the chemicals being absorbed or emitted by the light source.
Answer: 117.8 nm
Explanation:
Given,
Nonreflective coating refractive index : n = 1.21
Index of refraction:
= 1.52
Wave length of light = λ = 570 nm = 


Hence, the minimum thickness of the coating that will accomplish= 117.8 nm
Answer:
IGNEOUS ROCKS
Explanation: Igneous rocks are those rocks that solidify from magma.
Igneous rock is divided into two ,they are:
1. Intrusive
Igneous rocks crystallized belowearth"s crust. Its cooling material is called lava.
2 Extrusive igneous rock is also known as known as volcanic rocks